COLLOID MEDIATED DRUG TRANSPORT ACROSS DERMAL ROUTE: A CRITICAL REVIEW

Abstract

Pressure techniques or Focussed forces like sonic pulses, voltage pulses, ballistic treatment or optoporation by Laser beam and use of penetration enhancers are more often invasive to overcome the multiple barrier function of skin. Now, the colloidal systems are getting preference to be used transdermally. The colloidal systems include some basic structures like micelles, liposomes, nanoparticles, dendrimers, micro- and nanoemulsions etc. Again, for transdermal flux of any colloidal aggregate, the system must possess sufficient adaptability property depending upon the pore width, so to make a path way for its entry. The adaptability or deformability of the colloidal aggregate is a function of its composition. Micelles with long shape structures are flexible and depend upon binary phase composition. Vesicular or globular forms get the deformable nature by using lipid and membrane softener (bio surfactants) mixture. The diffusion or molecular barrier penetration of colloids need a driving force, which is provided by the trans-barrier hydration free energy gradient created internally or externally of and by the system. Some ultra deformable colloidal carriers like Transferosomes, Ethosomes, Aquasomes and Niosomes are potential systems for transport across the skin. However, this broad research area of colloids still needs much orientation and attention by researchers, rather than going for older invasive techniques.